It might be that I have to work on my search skills but I have not found any information on how veterancy works in BA. I can see ingame that units get more HP with experience, but what are the rules?
Is there a cap on max HP?
Is 1 kill = XX HP points? For all units?
Are there other changes with higher veterancy? Etc etc.

Thank you for your time.
/K

Seems to me like theres no cap on exp, but after getting the silver star units only gain hp very, very slowly.
Once had a golli with almost 10k hp though (used him as a hit & run/repair weapon on the middle on folsomdam), he had something like 2.5 experience I think.

From my observations, ROF (and therefore DPS too) seems to increase too with gained experience.

This is not limited to BA.

XP gain for damaging a unit = 0.1 * experienceMult * damage / target's HP * target's power / attacker's power.
XP gain for killing a unit = 0.1 * experienceMult * target's power / attacker's power.
Default power is equal to metal cost + energy cost / 60. (This is the only use of "power".) Default experienceMult is 1.0.

Bonus factor = 1 + xp / (xp + 1).

Power multiplier = powerScale * bonus factor.
powerScale defaults to 1.0.

HP multiplier = healthScale * bonus factor.
healthScale defaults to 0.7.

Rate of fire multiplier = reloadScale * bonus factor.
reloadScale defaults to 0.4.

Also weapons get varying accuracy bonuses with XP, but I CBA to describe it exactly here.

Read gamedata/modrules in the mod itself to find the values for that mod.

Some notes:

At default values, you get 0.1 XP for bringing something of your own power down to 0 HP, and another 0.1 XP for landing the killing blow.

At 1 XP, you get half the benefits of being at infinity XP. For example, if you get +20% rate of fire at 1 XP, you'll have +40% rate of fire at infinity XP.